Washington — For any medical schools that haven’t finished their ethics homework, a Republican senator is handing out an extra writing assignment.

The American Medical Student Association and the Pew Prescription Project last week announced the results of their annual survey on conflict-of-interest rules, giving 45 of 149 medical schools a grade of A or B for their policies governing pharmaceutical-industry interactions with their faculty members and students.

But 23 schools contacted for the survey didn’t reply, and Sen. Charles E. Grassley of Iowa, the top Republican on the Senate Finance Committee, is now going after them. Mr. Grassley wrote today to the 23 schools, saying he wants them to provide his office, by July 15, with the same information on their ethics policies that they did not provide to the American Medical Student Association.

“Disclosure of those ties would help to build confidence that there’s nothing to hide,” the senator said in a written statement.

Officials at some of the schools listed by the student association as not cooperating have already said, however, that it was apparently just a misunderstanding.

“It was like a homework assignment we never got,” Michael L. Good, interim dean of the College of Medicine at the University of Florida, told The Gainesville Sun. “But it’s not like we’ve been ignoring the subject,” Dr. Good said, noting that the medical school has a longstanding policy on potential conflicts of interest that just went through an update.

In addition to the University of Florida, the schools cited by Mr. Grassley are the Arizona College of Osteopathic Medicine, Edward Via Virginia College of Osteopathic Medicine, Medical College of Georgia School of Medicine, Northeastern Ohio University College of Medicine, Philadelphia College of Osteopathic Medicine, Rocky Vista University College of Osteopathic Medicine, Tulane University School of Medicine, University of Nevada School of Medicine, Albany Medical College, Chicago College of Osteopathic Medicine, Dartmouth Medical School, Howard University College of Medicine, Lake Erie College of Osteopathic Medicine, Louisiana State University School of Medicine-New Orleans, Meharry Medical College, Morehouse School of Medicine, New York College of Osteopathic Medicine of the New York Institute of Technology, Ponce School of Medicine, San Juan Bautista School Of Medicine, State University of New York at Buffalo School of Medicine, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, and University of South Carolina School of Medicine. —Paul Basken